I will start the replies off by saying Ashdown
either a MAG series combo, maybe second hand if you want the 2x10 or the Electric Blue range, new although they only do it in 1x12 or 1x15.http://www.ashdownmusic.co.uk/bass/index.asp
one of the cheapest places to find Ashdown and many others is www.soundslive.co.uk
good luck